[FEATURE-REQUEST]vaex concat: Add a hierarchical index at the outermost level of the data.

[oan-Dev05]

Vaex concat with keys In pandas for concatenation along with keys is done like this: df = pd.concat([df1, df1], keys=[Dataframe 1', 'Dataframe 2']) So, how we can achieve this in vaex. help me out. Thanks!

[JovanVeljanoski]

You can use join in vaex.

[oan-Dev05]

@JovanVeljanoski thanks

[oan-Dev05]

@JovanVeljanoski I meant: axis=0 When concatenating Series objects along axis=0 (extending the index). Those keys, become a new initial level of a MultiIndex object in the index attribute. Example: pandas: pd.concat([df1, df2, df3], keys=['A', 'B', 'C'])

---

table column1 column 2 A 2 1 A 3 2 B 1 3 B 2 4 B 1 5 C 3 6 dtype: int64 ,

[JovanVeljanoski]

then you can use vaex.concat. Vaex has no concept of indices (so far).

[oan-Dev05]

thanks

[maartenbreddels]

I think the equivalent in vaex would be to manually add a column with the same name to each dataframe:

df['identifier'] = vaex.vconstant('A')

etc